A standard hypodermic syringe comprises a hollow body holding a liquid medicament and a piston. An open end of the body carries an inner cap in which is seated a needle so that, when the piston is advanced, the liquid is expressed through the needle.
In order to maintain sterility before use, especially when the syringe is supplied prefilled to the user, it is standard to provide a protector cap over the needle. This cap is removed before use.
The manufacture of such a syringe is fairly complex, in particular because the needle and outer end of the assembly must be maintained sterile. Thus during assembly it is necessary to provide several sterilizing steps as the various parts are fitted together. This manufacture is even more complex when high-temperature sterilization is required.